The mostly-morubund Hurd project is well known for what it's not: the kernel at the heart of the GNU/Linux system. But there's a long and interesting story about what it could have been, too. From Linux User magazine: "The design of the Hurd was an attempt to embody the spirit and promise of the free software movement in code." Those are mighty ambitions, and this story is as much about competing visions as competing kernels. Says Thomas Bushnell: "My first choice was to take the BSD 4.4-Lite release and make a kernel. I knew the code, I knew how to do it. It is now perfectly obvious to me that this would have succeeded splendidly and the world would be a very different place today." This is a well-written and fascinating read.

Whilst you're not wrong, the post you responded to is clearly an accurate correction of the OP, who was spouting complete nonsense. GNU existed before Linux, it enabled Linus to create Linux, and thus when Linux first became a bit of a hit, it was the GNU OS with Linux as a kernel. Naturally, over the nearly-20 years since, a lot of GNU has since been made obsolete or diverged from its GNU roots, but I don't recall anybody claiming otherwise.